High-definition display uses white OLED, color filters

TOKYO  Eastman Kodak Co. and Sanyo Electric Co. Ltd. have developed an organic light emitting diode (OLED) display that employs a white organic electroluminescent material and color filters that may be applied to large, high-definition displays. Sanyo will demonstrate a 14.7-inch prototype of the display at the CEATEC Japan 2002 conference which begins Tuesday (Oct. 1) in Makuhari, Japan.

Earlier OLED prototypes include the 17-inch polymer-type display that Toshiba Corp. showed last April, and the 13-inch small-molecule display that Sony Corp. has had in prototype since February 2001. Both are "pixelized," consisting of red, green and blue electroluminescent dots.

The Kodak and Sanyo prototype sports a 16:9 aspect ratio and displays images using light emitted from a white EL layer and passed through color filters.

"The combination of a white electroluminescent material and a color filter does not require precise alignment as rigorous as pixelized OLED displays," said Kenichi Shibata, manager of Sanyo's display devices department. "The efficiency is a bit sacrificed by the filter, but this white electroluminescent and color filter-type display is suitable for large-sized, high-definition displays."

Separately, the joint OLED manufacturing venture of Kodak, Sanyo and SK Display, has started volume production of 2.2-inch active-matrix OLED panels. These displays do not use a color filter, but instead have pixelized red, green and blue emitting dots. "Pixelized-type OLEDs have higher efficiency, so it is suitable for applications that require lower power consumption," Shibata said. "We will offer both color filter type and pixelized OLEDs, depending on the application."